[PATCH 2/8] xfs: standardize ondisk to incore conversion for inode btrees

Darrick J. Wong
2022-12-30T22:38:28Z

Create a xfs_inobt_check_irec function to detect corruption in btree
records. Fix all xfs_inobt_btrec_to_irec callsites to call the new
helper and bubble up corruption reports.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/libxfs/xfs_ialloc.c | 61 ++++++++++++++++++++++++--------------
fs/xfs/libxfs/xfs_ialloc.h | 2 +
fs/xfs/libxfs/xfs_ialloc_btree.c | 2 +
fs/xfs/libxfs/xfs_ialloc_btree.h | 2 +
fs/xfs/scrub/ialloc.c | 24 ++-------------
5 files changed, 47 insertions(+), 44 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index 5118dedf9267..010d1f514742 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -95,33 +95,21 @@ xfs_inobt_btrec_to_irec(
irec->ir_free = be64_to_cpu(rec->inobt.ir_free);
}

-/*
- * Get the data from the pointed-to record.
- */
-int
-xfs_inobt_get_rec(
- struct xfs_btree_cur *cur,
- struct xfs_inobt_rec_incore *irec,
- int *stat)
+/* Simple checks for inode records. */
+xfs_failaddr_t
+xfs_inobt_check_irec(
+ struct xfs_btree_cur *cur,
+ const struct xfs_inobt_rec_incore *irec)
{
- struct xfs_mount *mp = cur->bc_mp;
- union xfs_btree_rec *rec;
- int error;
uint64_t realfree;

- error = xfs_btree_get_rec(cur, &rec, stat);
- if (error || *stat == 0)
- return error;
-
- xfs_inobt_btrec_to_irec(mp, rec, irec);
-
if (!xfs_verify_agino(cur->bc_ag.pag, irec->ir_startino))
- goto out_bad_rec;
+ return __this_address;
if (irec->ir_count < XFS_INODES_PER_HOLEMASK_BIT ||
irec->ir_count > XFS_INODES_PER_CHUNK)
- goto out_bad_rec;
+ return __this_address;
if (irec->ir_freecount > XFS_INODES_PER_CHUNK)
- goto out_bad_rec;
+ return __this_address;

/* if there are no holes, return the first available offset */
if (!xfs_inobt_issparse(irec->ir_holemask))
@@ -129,15 +117,41 @@ xfs_inobt_get_rec(
else
realfree = irec->ir_free & xfs_inobt_irec_to_allocmask(irec);
if (hweight64(realfree) != irec->ir_freecount)
+ return __this_address;
+
+ return NULL;
+}
+
+/*
+ * Get the data from the pointed-to record.
+ */
+int
+xfs_inobt_get_rec(
+ struct xfs_btree_cur *cur,
+ struct xfs_inobt_rec_incore *irec,
+ int *stat)
+{
+ struct xfs_mount *mp = cur->bc_mp;
+ union xfs_btree_rec *rec;
+ xfs_failaddr_t fa;
+ int error;
+
+ error = xfs_btree_get_rec(cur, &rec, stat);
+ if (error || *stat == 0)
+ return error;
+
+ xfs_inobt_btrec_to_irec(mp, rec, irec);
+ fa = xfs_inobt_check_irec(cur, irec);
+ if (fa)
goto out_bad_rec;

return 0;

out_bad_rec:
xfs_warn(mp,
- "%s Inode BTree record corruption in AG %d detected!",
+ "%s Inode BTree record corruption in AG %d detected at %pS!",
cur->bc_btnum == XFS_BTNUM_INO ? "Used" : "Free",
- cur->bc_ag.pag->pag_agno);
+ cur->bc_ag.pag->pag_agno, fa);
xfs_warn(mp,
"start inode 0x%x, count 0x%x, free 0x%x freemask 0x%llx, holemask 0x%x",
irec->ir_startino, irec->ir_count, irec->ir_freecount,
@@ -2705,6 +2719,9 @@ xfs_ialloc_count_inodes_rec(
struct xfs_ialloc_count_inodes *ci = priv;

xfs_inobt_btrec_to_irec(cur->bc_mp, rec, &irec);
+ if (xfs_inobt_check_irec(cur, &irec) != NULL)
+ return -EFSCORRUPTED;
+
ci->count += irec.ir_count;
ci->freecount += irec.ir_freecount;

diff --git a/fs/xfs/libxfs/xfs_ialloc.h b/fs/xfs/libxfs/xfs_ialloc.h
index 9bbbca6ac4ed..fa67bb090c01 100644
--- a/fs/xfs/libxfs/xfs_ialloc.h
+++ b/fs/xfs/libxfs/xfs_ialloc.h
@@ -92,6 +92,8 @@ union xfs_btree_rec;
void xfs_inobt_btrec_to_irec(struct xfs_mount *mp,
const union xfs_btree_rec *rec,
struct xfs_inobt_rec_incore *irec);
+xfs_failaddr_t xfs_inobt_check_irec(struct xfs_btree_cur *cur,
+ const struct xfs_inobt_rec_incore *irec);
int xfs_ialloc_has_inodes_at_extent(struct xfs_btree_cur *cur,
xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
int xfs_ialloc_has_inode_record(struct xfs_btree_cur *cur, xfs_agino_t low,
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index fb10760fd686..e849faae405a 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -610,7 +610,7 @@ xfs_iallocbt_maxlevels_ondisk(void)
*/
uint64_t
xfs_inobt_irec_to_allocmask(
- struct xfs_inobt_rec_incore *rec)
+ const struct xfs_inobt_rec_incore *rec)
{
uint64_t bitmap = 0;
uint64_t inodespbit;
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.h b/fs/xfs/libxfs/xfs_ialloc_btree.h
index 26451cb76b98..6d8d6bcd594d 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.h
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.h
@@ -55,7 +55,7 @@ struct xfs_btree_cur *xfs_inobt_stage_cursor(struct xfs_mount *mp,
extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int);

/* ir_holemask to inode allocation bitmap conversion */
-uint64_t xfs_inobt_irec_to_allocmask(struct xfs_inobt_rec_incore *);
+uint64_t xfs_inobt_irec_to_allocmask(const struct xfs_inobt_rec_incore *irec);

#if defined(DEBUG) || defined(XFS_WARN)
int xfs_inobt_rec_check_count(struct xfs_mount *,
diff --git a/fs/xfs/scrub/ialloc.c b/fs/xfs/scrub/ialloc.c
index fd5bc289de4c..9aec5a793397 100644
--- a/fs/xfs/scrub/ialloc.c
+++ b/fs/xfs/scrub/ialloc.c
@@ -119,15 +119,6 @@ xchk_iallocbt_chunk(
return true;
}

-/* Count the number of free inodes. */
-static unsigned int
-xchk_iallocbt_freecount(
- xfs_inofree_t freemask)
-{
- BUILD_BUG_ON(sizeof(freemask) != sizeof(__u64));
- return hweight64(freemask);
-}
-
/*
* Check that an inode's allocation status matches ir_free in the inobt
* record. First we try querying the in-core inode state, and if the inode
@@ -431,24 +422,17 @@ xchk_iallocbt_rec(
int holecount;
int i;
int error = 0;
- unsigned int real_freecount;
uint16_t holemask;

xfs_inobt_btrec_to_irec(mp, rec, &irec);
-
- if (irec.ir_count > XFS_INODES_PER_CHUNK ||
- irec.ir_freecount > XFS_INODES_PER_CHUNK)
- xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
-
- real_freecount = irec.ir_freecount +
- (XFS_INODES_PER_CHUNK - irec.ir_count);
- if (real_freecount != xchk_iallocbt_freecount(irec.ir_free))
+ if (xfs_inobt_check_irec(bs->cur, &irec) != NULL) {
xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+ return 0;
+ }

agino = irec.ir_startino;
/* Record has to be properly aligned within the AG. */
- if (!xfs_verify_agino(pag, agino) ||
- !xfs_verify_agino(pag, agino + XFS_INODES_PER_CHUNK - 1)) {
+ if (!xfs_verify_agino(pag, agino + XFS_INODES_PER_CHUNK - 1)) {
xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
goto out;
}